The curvature structure unlocks an ultra-efficient metal-free carbon catalyst surpassing gold for acetylene hydrochlorination  

曲率结构解锁超高效非金属碳催化剂:乙炔氢氯化催化性能超黄金催化剂

作　　者：Shuhao Wei Ye Chen Yiyang Qiu Wei Kong Di Lin Jiarong Li Guojun Lan Yi Jia Xiucheng Sun Zaizhe Cheng Jian Liu PHu Ying Li 魏抒豪;陈烨;邱一洋;孔薇;林迪;李佳容;蓝国钧;贾毅;孙秀成;程载哲;刘健;胡培君;李瑛(浙江工业大学化工学院,工业催化研究所,浙江杭州310014;上海科技大学物理科学与技术学院,上海201210;浙江工业大学莫干山研究院,浙江德清313200;内蒙古大学化学化工学院,内蒙古呼和浩特010021;贝尔法斯特女王大学化学与化学工程学院,英国贝尔法斯特)

机构地区：[1]Institute of Industrial Catalysis,College of Chemical Engineering,Zhejiang University of Technology,Hangzhou 310014,Zhejiang,China [2]School of Physical Science and Technology,Shanghai Tech University,Shanghai 201210,China [3]Moganshan Institute,Zhejiang University of Technology,Deqing 313200,Zhejiang,China [4]College of Chemistry and Chemical Engineering,Inner Mongolia University,Hohhot 010021,Inner Mongolia,China [5]School of Chemistry and Chemical Engineering,Queen’s University Belfast,Belfast,UK

出　　处：《Chinese Journal of Catalysis》2025年第3期260-271,共12页催化学报(英文)

基　　金：国家重点研发项目(2024YFC3907904);2019年“稀土、煤化工”项目资助和内蒙古自治区科技攻关项目(2019ZD017).

摘　　要：Metal-free carbon catalysts have garnered significant attention since their inception.Despite substantial advancements,including widely adopted strategies such as heteroatom doping and defect engineering,their catalytic performance remains inferior to that of metal-based catalysts.In this study,we have predicted and demonstrated that the curvature of carbon plays a pivotal role in the adsorption of acetylene and the overall catalytic performance.First-principles calculations suggest that a tip-enhanced local electric field at the defect site on the curved carbon catalyst enhances the reaction kinetics for acetylene hydrochlorination.The experimental results highlight the structural advantages of the curved defect site,revealing that high-curvature defective carbon(HCDC)demonstrates an adsorption capacity for acetylene that is almost two orders of magnitude higher than that of defective carbon.Notably,HCDC achieves an acetylene conversion of up to 90%at 220℃under a gas hourly space velocity of 300 h^(-1),significantly surpassing the performance of the benchmark 0.25%Au/AC catalyst.This proof-of-concept study reveals the fundamental mechanisms driving the superior performance of carbon catalysts with curved nanostructures and presents a straightforward,environmentally friendly method for large-scale production of carbon materials with precisely controlled nanostructures.It highlights the potential for commercializing metal-free carbon catalysts in acetylene hydrochlorination and related heterogenous catalytic reactions.聚氯乙烯(PVC)是由氯乙烯(VCM)聚合而成的,是我国产能最大的高分子材料之一.目前,工业上广泛采用活性炭负载氯化汞催化剂用于生产氯乙烯.随着国际限汞政策的逐步实施,开发新型无汞催化剂迫在眉睫.目前能替代汞催化剂的有金、钌、铂等贵金属催化剂和铜、铋等非贵催化剂系列,但这些催化剂都存在成本高、易烧结、金属流失等问题.而非金属碳催化剂因其绿色环保、成本低廉且无金属烧结和流失等优势,成为最具潜力的无汞催化剂之一.尽管研究人员已经通过掺杂杂原子和构造缺陷结构等各种策略有效提高了碳催化剂的乙炔氢氯化性能,但与目前报道的性能最好的黄金催化剂相比,其在活性上仍存在较大差距.我们通过对纳米碳催化剂的表面曲率结构调控,大幅度提高了碳催化剂的乙炔氢氯化活性,并通过理论计算和实验研究,揭示了碳催化剂的高曲率缺陷结构对乙炔氢氯化催化性能的增强机制.首先通过理论计算研究了氮掺杂石墨烯的平面结构、凸面曲率结构和凹面曲率结构对乙炔及氯化氢的吸附行为,发现当石墨烯形成曲率结构后,会在曲率尖端活性位点周围形成一个尖端增强的局部电场,显著增强了碳催化剂对乙炔分子的吸附,并促进氯化氢的活化,从而大幅度降低乙炔氢氯化反应的能垒,促进反应的进行.本文以聚丙烯腈为炭源,通过纳米氧化硅模板及两步控氧炭化的策略实现了高曲率富缺陷碳基催化剂(HCDC)的精准可控制备.与无曲率富缺陷碳(DC)催化剂相比,HCDC表现出极佳的催化性能.在反应温度为220℃,乙炔空速为300 h^(-1),氯化氢和乙炔进料比为1.2的反应条件下,HCDC碳催化剂上的乙炔转化率高达90%,而普通DC碳催化剂的乙炔转化率只有30%左右.动力学研究发现,在高曲率的碳催化剂表面,乙炔氢氯化遵循ER机理,乙炔的反应级数为-0.16,反应活化能仅为31

关 键 词：METAL-FREE Carbon catalyst CURVATURE Acetylene hydrochlorination Carbocatalysis 

分 类 号：O643.3[理学—物理化学]